[FLASH-USERS] Current does not flow through areas with high conductivity in flash

[lizy]

Dear Flash developers and engineers,
 
In two-dimensional axisymmetric simulation, a thin metal wire with high resistivity (diameter of tens of micrometers) flows through a current, and the metal wire is surrounded by a vacuum outside. Within a hundred nanoseconds, the actual situation should be that the current flows through a low resistivity region, but currently, due to the magnetic field diffusing from the outside to the inside, the internal metal diffusion coefficient is too low. Now the current is concentrated at the vacuum metal boundary rather than in the metal region. I used an implicit resistivitySolver, but the final result did not match reality. Is there any good solution?
 
In addition, the process of implicit magnetic diffusion should be a solution to the evolution of the global magnetic field, and the magnetic field should have diffused at the initial moment. However, the current implicit magnetic diffusion in flash seems to involve calculating the diffusion of the magnetic field at each time step, resulting in slow diffusion in areas with low magnetic diffusion coefficients. I still don't quite understand the process of magnetic diffusion.  I would especially appreciate your patient answe！ 
 
                                                                         Lizy
 
                                                              30,May,2024
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